This invention relates to audiometers and is particularly directed to audiometers employing frequency modulated radio means for communicating between the testing device and one or more patients being tested.
Audiometers have long been used to test the hearing of a patient by generating audio signals at various pitches and amplitudes. Conventionally, these audio signals have been supplied to a patient by means of wires connected to the earphones of a headset worn by the patient. The pitch and amplitude of the audio signals are varied, more or less randomly, and the signals are selectively directed to one or the other of the patient's earphones, in response to which the patient is asked to indicate when they hear a signal and which ear they hear it in.
As indicated above, the prior art audiometers have communicated the test signals to the patient by means of wires. However, this means that the wires of the patient's headset must be physically connected to the test device, which greatly limits the mobility of the patient and restricts the number of patients who can be tested at a given time.
A search in the U.S. Patent Office has revealed the following:
______________________________________ U.S. Pat. No. Inventor Issued ______________________________________ 3,808,354 M. Feezor April 30, 1974 3,809,811 J. Delisle et al May 7, 1974 3,906,158 J. D. Lake Sept. 16, 1975 3,974,335 V. O. Blackledge Aug. 10, 1976 4,109,106 R. Voss Aug. 22, 1978 4,157,456 R. Voss June 5, 1979 4,334,315 H. Ono et al June 8, 1982 4,539,708 E. G. Norris Sept. 3, 1985 4,369,521 T. Sawada June 18, 1983 4,667,683 R. S. Dugot May 26, 1987 ______________________________________
The patents to Voss, Lake and Blackledge each relate to audiometric devices which communicate with the patient by means of wires. The patent to Ono et al teaches the use of miniaturized frequency modulated (FM) radio equipment for various communication applications, but does not suggest that it would have any use in audiometric testing. The remaining patents are of general interest only.